Cordless power tools may be powered by portable, removable, rechargeable battery packs. In use, the battery packs powering cordless power tools may be discharged faster than the battery packs can be charged. In many environments, charging power sources (e.g., AC outlet, DC cigarette lighter outlet, etc.) are often unavailable, and/or inaccessible, and/or cannot provide enough power and energy to keep up with demand.